CO2 separation device for internal combustion engine

The present invention addresses the problem of providing a CO2 separation device for an internal combustion engine capable of satisfactorily adsorbing and desorbing CO2 by a CO2 adsorbent by maintaining the temperature of exhaust gas supplied to the CO2 adsorbent at an appropriate temperature. Furthermore, provided is a CO2 separation device for an internal combustion engine, with which it is possible to prevent overheating of the CO2 adsorbent even when the temperature of the exhaust gas is excessively increased. To this end, this CO2 separation device for an internal combustion engine, which is provided in the exhaust system of the internal combustion engine and separates CO2 from exhaust gas, is provided with: an exhaust passage that is connected to the internal combustion engine and through which the exhaust gas flows; a CO2 adsorption material which is provided in the exhaust passage, adsorbs CO2 in the exhaust gas at a given low temperature, and desorbs the adsorbed CO2 at a given high temperature; and